Vijay Posted October 12, 2016 Share Posted October 12, 2016 My architect advised 75mm of Celotex FF4000 and 150mm of Celotex XR4000 to get a U value of 0.11 but thanks to some posts on a previous thread, I'm looking at other insulation. So far I've got some prices for the following: Celotex FI5000 75mm - £35.14 Celotex XR4000 150mm - 38.16 Xtratherm pitched roof board (was told it's used for floors too) 70mm - £19.00 Xtratherm 150mm - £34.50 Recticel Eurothane 75mm - £22.85 Recticel Eurothane 150mm - £44.00 What do you guys think of those prices and what other manufacturers would you recommend? Cheers Vijay Link to comment Share on other sites More sharing options...
CC45 Posted October 12, 2016 Share Posted October 12, 2016 I used xr4150 plus xr4075 under our floor. Worked fine, don't think you need the 'proper' floor equivalent. Held the ufh staples (65mm) no problem Link to comment Share on other sites More sharing options...
Declan52 Posted October 12, 2016 Share Posted October 12, 2016 I used xtratherm for my floor and the roof. As you said it was the same stuff. Link to comment Share on other sites More sharing options...
AliG Posted October 12, 2016 Share Posted October 12, 2016 (edited) Same here, my builder priced up FF instead of XR due to UFH. It is way more expensive and unnecessary. Just reread your post, your Xtratherm prices are v low. I think that's your best bet. Edited October 12, 2016 by AliG Link to comment Share on other sites More sharing options...
bassanclan Posted October 13, 2016 Share Posted October 13, 2016 Have you considered using EPS? It's much cheaper and its more waterproof Link to comment Share on other sites More sharing options...
CC45 Posted October 13, 2016 Share Posted October 13, 2016 Xr4150 £37.89 8x4 sheet. Dec 2015 Ga4075 £20.61 8x4 sheet Dec 2015 Local merchant - on an 10k order SIG were £70 cheaper. Went local. Cc Link to comment Share on other sites More sharing options...
Vijay Posted October 13, 2016 Author Share Posted October 13, 2016 3 hours ago, bassanclan said: Have you considered using EPS? It's much cheaper and its more waterproof Happy to consider that. Is there any downsides to using EPS? Link to comment Share on other sites More sharing options...
joe90 Posted October 13, 2016 Share Posted October 13, 2016 I am using EPS, 300mm. Link to comment Share on other sites More sharing options...
PeterW Posted October 13, 2016 Share Posted October 13, 2016 Going for EPS 250mm - only because 300mm with the weird PA ratio we have gives 0.01 difference on the uValue which equates to 37p a year on heating ... 1 Link to comment Share on other sites More sharing options...
Vijay Posted October 13, 2016 Author Share Posted October 13, 2016 And there's no issue with UFH/clips with EPS? Link to comment Share on other sites More sharing options...
PeterW Posted October 13, 2016 Share Posted October 13, 2016 2 hours ago, Vijay said: Happy to consider that. Is there any downsides to using EPS? Only downside is depth - on top of beam and block it would be very thick. If you are still going that route look at the Tetris or Jabfloor solution for EPS beam infil. Much lighter and easier to work with than blocks. Link to comment Share on other sites More sharing options...
Vijay Posted October 13, 2016 Author Share Posted October 13, 2016 No, I'm going down the concrete block route as I need a working floor and I'm happy to lay the blocks myself anyway Link to comment Share on other sites More sharing options...
PeterW Posted October 13, 2016 Share Posted October 13, 2016 Don't understand the working floor comment - you can walk on the tetris system as you lay it, and you take out a step by laying the floor and insulation in one go. Or are you saying you want to go with B&B until you have a shell then put UFH and screed..? If so you don't want EPS as its too thick as you'll end up with an additional 200mm or so depth to work with... Link to comment Share on other sites More sharing options...
Vijay Posted October 13, 2016 Author Share Posted October 13, 2016 By working floor I mean the beam and blocks will go down and that's it. I want to know the insulation I'll use in the future when I'm ready to put the UFH and screed down, so I can work out levels now. So if using EPS, would I use less than PIR and still get the same U value? 1 Link to comment Share on other sites More sharing options...
PeterW Posted October 13, 2016 Share Posted October 13, 2016 No EPS needs more - so 2-300mm vs 140-170mm PIR Link to comment Share on other sites More sharing options...
Vijay Posted October 13, 2016 Author Share Posted October 13, 2016 Cheers Peter, gives me more to consider Link to comment Share on other sites More sharing options...
Oz07 Posted October 14, 2016 Share Posted October 14, 2016 the kitchen in my house has 6"pir, cross bonded and installed reasonably well. Why does the tiled surface feel cold. I know its something to do with relativity BUT I wonder if it would feel cooler with only 4", or 2" of PIR?! I know the science says it shouldn't, but I can't comprehend. Link to comment Share on other sites More sharing options...
daiking Posted October 14, 2016 Share Posted October 14, 2016 41 minutes ago, Oz07 said: the kitchen in my house has 6"pir, cross bonded and installed reasonably well. Why does the tiled surface feel cold. I know its something to do with relativity BUT I wonder if it would feel cooler with only 4", or 2" of PIR?! I know the science says it shouldn't, but I can't comprehend. I've got a tiled area that has 3 subfloor - Concrete slab with 100mm EPS + 100mm PIR, suspended wooden floor with 125mm PIR between joists and suspended wooden floor with no insulation. The tiles on the concrete 'feels' warmer than the other. YMMV. One day soon I really will buy that laser IR thermometer to check it out properly. Link to comment Share on other sites More sharing options...
DavidFrancis Posted October 14, 2016 Share Posted October 14, 2016 Oz - I'm no physicist, but isn't it all to do with the temperature of the floor, the temperature of your feet, and the (thermal) conductivity of the floor surface and its specific heat capacity. As long as your feet are warmer than the floor it's going to feel cool, but a surface with high conductivity is going to feel cooler than one with low conductivity as it wicks away the heat from your feet that much faster (and possibly the effect is even more pronounced in a material with high specific heat capacity as can absorb more heat without its temperature increasing so fast). If it's of any interest I've just IRed my feet and the temperature varies from about 19C at my toes to 26 in the arch, but I have cold feet! The (barely insulated) floor where I'm sitting is about 16.5 (room temp about 18) Will be interested to see the response of some one more knowledgeable. Link to comment Share on other sites More sharing options...
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